Date   
Re: From 2014: Tektronix Announces Winner of Europe’s Oldest Working Oscilloscope Contest

Dave Daniel
 

Yes, after perusing my copy of "Oscilloscope Development, 1943-57" by Peter D. Hiscocks, I realize that one cannot beat a 511 as the earliest 'Tektronix 'scope.

When I was much younger, I had a Dumont 'scope that was given to me by an uncle who worked for Fisher Scientific. It did not have calibrated amplifier controls, which, at age 11 or so, confused me. I do not remember the model of that 'scope and I have wondered for years how old it was.

The original 511 was made available in 1948.

DaveD

On 9/15/2019 9:56 AM, Chuck Harris wrote:
The 310 is close, but no cigar.

The 511 was the original Tek scope, the 511AD was a
later refined model, with a distributed vertical amplifier.

My working (?) 513D is probably older than Alan's 511AD.

I give it a ? because although I went over it completely
about 30 years ago, it has the selenium rectifiers, which
tend to turn into insulators.

According to Stan G's book:

511 last catalog 1952
511AD last catalog 1955
513 last catalog 1953
513D last catalog 1953

310 last catalog 1958
310A last catalod 1971

-Chuck Harris

Dave Daniel wrote:
Hmmm.. I have (and had back in 2014) a working 310.

As cool as an MDO would be, and not that I want a 'scope that I can't repair when
(not if) it breaks, but there have to be hundreds of owners of vintage Tektronix
'scopes out there that own working 'scopes that are older than the 511 cited in the
post, Europe or not.

I don't recall hearing of this "contest". It is weird that it did not come to light
while it was in progress. Does anyone have any information about the the contest itself?

DaveD

Re: Tek 576 Curve Tracer HV Transformer winding

ykochcal
 

There are practice cores in most old electronics, which are everywhere
around here if you look.

In particular Old PC power supplies typically have one of similar size but
the wrong orientation.

I am under the opinion that if you break the core it may still be useable.
They have by design a fair gap in the center leg.
If you break the core you will most lily break off one side of the E
Then you just need to break the other side to match (that happened to me
anyway).
Then glue back together with very slow epoxy using a machinist vise and
clamp to keep it square while squeezing it so the gap is as small as
possible.

I ended up with a gap in each leg that I thought was about less then 20% or
so of the gap in the center.

The core seemed to work well, but after awhile that attempt failed due to a
short. I think that I did not put in added space when the winding went from
two wires to one at the end of the coil which doubled the voltage difference
per layer.

Haven't tried to rewind after that attempt
John

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of
Mlynch001
Sent: Sunday, September 15, 2019 10:51 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Tek 576 Curve Tracer HV Transformer winding

John,

I will try this again at a higher temp. You are very certainly right about
this. I have not done any "practice" since I don't have anything to
practice on. I guess this is my "practice" piece? I'm going to cut the
rest of the coil off and then go from there. I appreciate Chuck's offer,
but I really feel the need to try to do this on my own. I may break the
core, I may be successful or, in the end, I may give up and send it to
Chuck. If I break these ferrite cores, I may come crying to Chuck or others
for a replacement set. I appreciate your advice and insight. One way or
the other, I will get this thing fixed. It is a shame that one stupid part
has disabled an otherwise functioning instrument. Before it "cuts off", it
works beautifully.

Sincerely

--
Michael Lynch
Dardanelle, AR

Re: 2465 DVS Repair - was; Re: [TekScopes] Wanted; Person to repair Tektronix 2465 DVS

jhalbrecht
 

Assuming TP46 is the PCB edge side of R567 It has about 1VAC 60hz maybe a 20 ms dc offset. It doesn't change as I exit the error message or _fiddle_ with the triggering adjustments.

 - Jeff

On 9/15/2019 6:39 AM, Chuck Harris wrote:
The power inside of the 2465 supplies is pretty dirty from
an RF point of view. It is pretty quiet from a 2x60Hz point
of view.

How can you tell the difference?

The RF noise is composed of sliver thin spikes that ride on
the top and bottom of the supply's DC waveform. They look like
a fuzzy caterpillar.

The 2x60Hz ripple will stand still when the scope is triggered
using the line mode.

Tek recommends you use the scope in bandwidth limit mode for
making these measurements.

The other failure that can happen to cause the Test05 Fail XX
failures is in the MUX and Sample and hold gates that the A5
board uses to feed the threshold signals to the trigger hybrid.

Typically one of three things happens (In approximately the
order of likelihood):

The MUX has an output that gets stuck high, or low (the message
gives a clue), or,

The sample and hold op amp gets stuck high or low, or,
The sample and hold capacitor gets leaky.

Trace back the TLA and TLB signals from the trigger hybrid to
the two sample and hold OPAMPS, and from there to the MUX.

And, it is conceivable that the AC Line signal that is supposed
to go from the power supply to the CHN5 input to the trigger hybrid
could be missing, or stuck... TP46 is your friend.

-Chuck Harris


jhalbrecht wrote:
O.K. tried without success to improve the ripple signal on the DC test points. I
don't have a dedicated ground on the Rigol nor on an old 15mhz B&K I aoso tried. I
tried with the banana clip between the 2464 ground jack and the ground of the test
signal on the rigol and on the outside of a BNC connector on CH2 of the Rigol. I
tried it like that with and without the addition of the probe ground too. Nothing got
me near to what I thought ripple might look like.

Is there any change the DC is that dirty?

I also tried swapping out the U300 trigger hybrid from the 2445 switch and knob
donor. Nope, same error Test 05 Fail 42

- Jeff


On 9/14/2019 4:59 AM, Chuck Harris wrote:
That won't do it!

You must connect a big fat banana plug terminated cable in the
2465's ground jack (near the calibrator) to the equivalent ground
on the front panel of the scope that is measuring the ripple.

Anything less will allow the ground loop current to pass through
the probe's shield, and the current through the probe's shield will
generate tens of millivolts (I2R) of unnecessary ground loop noise
in your signal.

We are dealing with a maximum of a few mv of signal here.

Strap the two scopes' grounds together!

-Chuck Harris


jhalbrecht wrote:
:-) yup. Connected the short ground clip from my probe to the solder ground lug on
the chassis / bnc of ch 1. Also set 20mhz bw filter too.

- Jeff


On 9/13/2019 9:11 PM, Chuck Harris wrote:
While doing the ripple measurement, you must connect the
grounds between the 2465 and the testing scope.

-Chuck Harris

jhalbrecht wrote:
Before trying the hybrid swap I got a bit more familiar with my 2465 by testing the
voltages on J119 and comparing to table 5-1 in the adjustment procedure.

I used a Keithley 2000 Multimeter and a Rigol DS1054z oscilloscope with the extra
options enabled.

The measurements looked solid and stable well withing the published tolerances.

However I'm not confident on my procedures for measuring ripple. It seemed more
like
stray noise basically at 120Hz I tried with the Keithley on AC and the Rigol
with AC
coupling. All the ripple appeared well below 100mv but for instance on pin 6, 12
and
5 that exceeds the 15mv spec as well as the 10mv spec for pin 1.

Before actually physically swapping the trigger hybrid are there any other test
suggestions to try first?


- Jeff

On 9/12/2019 11:11 AM, Chuck Harris wrote:
Hi Jeff,

Usually, when I see Test05, Fail XX, and it isn't the A5 board
of a late model 2465B, it is due to a bad trigger hybrid. Try
removing one from one of your 2445's, and put it into your DVS.
I would bet it will fix the problem.

Note: Seat the chip by hand, making sure it goes all the way
to the PCB. Then while holding it, put nuts on diagonal corners,
and snug them finger tight. Then put on the other two nuts.

Tightness doesn't improve the contacts, it just breaks the board
and studs. No more than 1/8T beyond contact. Just enough to
make the lock washer grab, no more.

Do measure the power supply's voltages and ripple. Don't tweak
any adjustments, unless you want to do a complete recalibration.

The capacitors are almost certainly dead by now... especially
if the fan is stopped, or sluggish from lack of lubrication.

-Chuck Harris

jhalbrecht wrote:
I got the paddle switch out of the donor without incident.

Chuck and group,

Perhaps I could check some voltages on the 2465 dvs (original / first model) A5
board
next in an attempt to solve the "Test 05 Fail 42' triggering problem before
digging
into replacing the paddle switch into the 2465 switch board assembly.

- Jeff



Re: Tek 576 Curve Tracer HV Transformer winding

Chuck Harris
 

Just remember the ferrite is a ceramic mixture,
so it was once heated much hotter than your oven
will ever go.

Good gloves so you don't burn yourself, don't worry
about the winding. Soak it in the oven, and then
remove it and with two hands give the top half and
the bottom half a twist, like you were removing a
jar lid.

If that doesn't work, up the temperature.

If you break it, don't cry. A drop of thin crazy
glue, and carefully aligning it back together, and
you will never know you did it... electrically.

A dry trial fit is a good idea, and a little compressed
air to remove any extra bits of ferrite sand that may
be in the way of a good fit.

-Chuck Harris

Mlynch001 wrote:

John,

I will try this again at a higher temp. You are very certainly right about this. I have not done any “practice” since I don’t have anything to practice on. I guess this is my “practice” piece? I’m going to cut the rest of the coil off and then go from there. I appreciate Chuck’s offer, but I really feel the need to try to do this on my own. I may break the core, I may be successful or, in the end, I may give up and send it to Chuck. If I break these ferrite cores, I may come crying to Chuck or others for a replacement set. I appreciate your advice and insight. One way or the other, I will get this thing fixed. It is a shame that one stupid part has disabled an otherwise functioning instrument. Before it “cuts off”, it works beautifully.

Sincerely

Re: 2465 DVS Repair - was; Re: [TekScopes] Wanted; Person to repair Tektronix 2465 DVS

Chuck Harris
 

It should be exactly 0.8Vp-p, with no offset. See the waveform
picture in the manual.

The scope's power on test routing attempts to measure the peaks
of that sine'ish waveform as a verification of the trigger and DAC
circuitry. Your scope is failing this test.

The first digit of the error code can be 0, 2, or 4.

4 means that the positive peak of the sinewave is too positive.

The second digit of the error code can be 0, 1, 2, or 4.

2 means that the negative peak is not negative enough.

That means, your sinewave appears to the controller as being
shifted up in the positive direction.

That is what you want to look for. Since the test signal goes
directly to the trigger chip, and if carefully measured will probably
be just right, the problem has to be that the trigger hybrid's
threshold is not being set correctly.

If your other knobs work ok when you press A/B and dismiss the error
message, the DAC has to be ok.

That leaves a bad MUX, or an opamp with a stuck output. I don't recall
which way a bad capacitor in the Sample gate goes, but you should be
able to see any of these errors, as they will stay stuck all of the
time.

-Chuck Harris

jhalbrecht wrote:

Assuming TP46 is the PCB edge side of R567 It has about 1VAC 60hz maybe a 20 ms dc
offset. It doesn't change as I exit the error message or _fiddle_ with the triggering
adjustments.

- Jeff

On 9/15/2019 6:39 AM, Chuck Harris wrote:
The power inside of the 2465 supplies is pretty dirty from
an RF point of view. It is pretty quiet from a 2x60Hz point
of view.

How can you tell the difference?

The RF noise is composed of sliver thin spikes that ride on
the top and bottom of the supply's DC waveform. They look like
a fuzzy caterpillar.

The 2x60Hz ripple will stand still when the scope is triggered
using the line mode.

Tek recommends you use the scope in bandwidth limit mode for
making these measurements.

The other failure that can happen to cause the Test05 Fail XX
failures is in the MUX and Sample and hold gates that the A5
board uses to feed the threshold signals to the trigger hybrid.

Typically one of three things happens (In approximately the
order of likelihood):

The MUX has an output that gets stuck high, or low (the message
gives a clue), or,

The sample and hold op amp gets stuck high or low, or,
The sample and hold capacitor gets leaky.

Trace back the TLA and TLB signals from the trigger hybrid to
the two sample and hold OPAMPS, and from there to the MUX.

And, it is conceivable that the AC Line signal that is supposed
to go from the power supply to the CHN5 input to the trigger hybrid
could be missing, or stuck... TP46 is your friend.

-Chuck Harris


jhalbrecht wrote:
O.K. tried without success to improve the ripple signal on the DC test points. I
don't have a dedicated ground on the Rigol nor on an old 15mhz B&K I aoso tried. I
tried with the banana clip between the 2464 ground jack and the ground of the test
signal on the rigol and on the outside of a BNC connector on CH2 of the Rigol. I
tried it like that with and without the addition of the probe ground too. Nothing got
me near to what I thought ripple might look like.

Is there any change the DC is that dirty?

I also tried swapping out the U300 trigger hybrid from the 2445 switch and knob
donor. Nope, same error Test 05 Fail 42

- Jeff


On 9/14/2019 4:59 AM, Chuck Harris wrote:
That won't do it!

You must connect a big fat banana plug terminated cable in the
2465's ground jack (near the calibrator) to the equivalent ground
on the front panel of the scope that is measuring the ripple.

Anything less will allow the ground loop current to pass through
the probe's shield, and the current through the probe's shield will
generate tens of millivolts (I2R) of unnecessary ground loop noise
in your signal.

We are dealing with a maximum of a few mv of signal here.

Strap the two scopes' grounds together!

-Chuck Harris


jhalbrecht wrote:
:-) yup. Connected the short ground clip from my probe to the solder ground lug on
the chassis / bnc of ch 1. Also set 20mhz bw filter too.

- Jeff


On 9/13/2019 9:11 PM, Chuck Harris wrote:
While doing the ripple measurement, you must connect the
grounds between the 2465 and the testing scope.

-Chuck Harris

jhalbrecht wrote:
Before trying the hybrid swap I got a bit more familiar with my 2465 by
testing the
voltages on J119 and comparing to table 5-1 in the adjustment procedure.

I used a Keithley 2000 Multimeter and a Rigol DS1054z oscilloscope with the extra
options enabled.

The measurements looked solid and stable well withing the published tolerances.

However I'm not confident on my procedures for measuring ripple. It seemed more
like
stray noise basically at 120Hz I tried with the Keithley on AC and the Rigol
with AC
coupling. All the ripple appeared well below 100mv but for instance on pin 6, 12
and
5 that exceeds the 15mv spec as well as the 10mv spec for pin 1.

Before actually physically swapping the trigger hybrid are there any other test
suggestions to try first?


- Jeff

On 9/12/2019 11:11 AM, Chuck Harris wrote:
Hi Jeff,

Usually, when I see Test05, Fail XX, and it isn't the A5 board
of a late model 2465B, it is due to a bad trigger hybrid. Try
removing one from one of your 2445's, and put it into your DVS.
I would bet it will fix the problem.

Note: Seat the chip by hand, making sure it goes all the way
to the PCB. Then while holding it, put nuts on diagonal corners,
and snug them finger tight. Then put on the other two nuts.

Tightness doesn't improve the contacts, it just breaks the board
and studs. No more than 1/8T beyond contact. Just enough to
make the lock washer grab, no more.

Do measure the power supply's voltages and ripple. Don't tweak
any adjustments, unless you want to do a complete recalibration.

The capacitors are almost certainly dead by now... especially
if the fan is stopped, or sluggish from lack of lubrication.

-Chuck Harris

jhalbrecht wrote:
I got the paddle switch out of the donor without incident.

Chuck and group,

Perhaps I could check some voltages on the 2465 dvs (original / first model) A5
board
next in an attempt to solve the "Test 05 Fail 42' triggering problem before
digging
into replacing the paddle switch into the 2465 switch board assembly.

- Jeff






Re: 11801 NVRAM

Reginald Beardsley
 

FWIW I set up my 11801 using the internal trigger and feeding a ~100 kHz ramp from my 33622A. By making slight adjustments to the ramp frequency I get a straight line which intersects the graticule all the way across the screen at 5 ps/div and 2 mV/div using 5120 points and at 1 ps/div with 1024 points. The internal timebase is not as stable as the 33622A which, despite not having the high stability option, has *very* little drift relative to a GPSDO from Leo Bodnar.

I'm obviously severely aliased to get a single cycle image of a 100 kHz ramp in a 10 or 50 ps wide window. That corresponds to 10 femtosecond sampling.

If there is a time base correction that was lost I don't see how I can measure it or what effect it might have. The ramp appears dead straight though it jumps around a lot because of the 4 ps jitter of the 11801 clock. By continually fiddling with the ramp frequency I can stop the display for a single sweep with a diagonal line over the full screen from upper right to lower left when collecting 5120 points.

I'm going to puzzle over this while I fix a rather late lunch. But I can't see how there is a significant issue. I should be able to do better getting digits via the GPIB interface and supplying a trigger signal from the 33622A.

As I removed the NVRAM battery to get it to boot before I replaced the NVRAM chip, there's no question that if there were cal data in the NVRAM chip it was lost.

Have Fun!
Reg

Re: Tek 576 Curve Tracer HV Transformer winding

Dave Daniel
 

On 9/15/2019 3:34 PM, Chuck Harris wrote:
Just remember the ferrite is a ceramic mixture,
so it was once heated much hotter than your oven
will ever go.
Ha. This reminds me of Jeff Potter's book "Cooking for Geeks", where he intentionally disables the self-cleaning interlock on his range to see how fast he can cook a pizza. ISTR that he got the oven temperature to well over 600^o.

DaveD

Re: Tek 576 Curve Tracer HV Transformer winding

ykochcal
 

Chuck is the 576 core the same as the 535, 545, and 585? I don't recall off
hand.

If so, there seems to be someone who scrapped a large number of scopes on
the bay and is selling the HV supply assemblies for about $24 in the USA

Searched "Tektronix transformer", sort by best match, but then look for the
worst match at the bottom.

So all is not lost in any case for a 576

John

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Chuck
Harris
Sent: Sunday, September 15, 2019 12:35 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Tek 576 Curve Tracer HV Transformer winding

Just remember the ferrite is a ceramic mixture,
so it was once heated much hotter than your oven
will ever go.

Good gloves so you don't burn yourself, don't worry
about the winding. Soak it in the oven, and then
remove it and with two hands give the top half and
the bottom half a twist, like you were removing a
jar lid.

If that doesn't work, up the temperature.

If you break it, don't cry. A drop of thin crazy
glue, and carefully aligning it back together, and
you will never know you did it... electrically.

A dry trial fit is a good idea, and a little compressed
air to remove any extra bits of ferrite sand that may
be in the way of a good fit.

-Chuck Harris

Mlynch001 wrote:
John,

I will try this again at a higher temp. You are very certainly right
about this. I have not done any "practice" since I don't have anything to
practice on. I guess this is my "practice" piece? I'm going to cut the
rest of the coil off and then go from there. I appreciate Chuck's offer,
but I really feel the need to try to do this on my own. I may break the
core, I may be successful or, in the end, I may give up and send it to
Chuck. If I break these ferrite cores, I may come crying to Chuck or others
for a replacement set. I appreciate your advice and insight. One way or
the other, I will get this thing fixed. It is a shame that one stupid part
has disabled an otherwise functioning instrument. Before it "cuts off", it
works beautifully.

Sincerely

561B Recapping

David Holland
 

Anyone recapped a Tektronix 561B, and have some pointers for capacitor
replacement specifications? (ESR/DF & ripple current ratings
particularly)

Looking up the Tektronix part numbers will lead to NSN numbers, which
will give original manufacturers, (Sprague/Mallory), and purported
original part numbers, that I can not find references to.

There's nothing I'm aware of specifically wrong with the scope at the
moment, other than 47 years on those caps - based on the 1972 date
codes, and a serial # in the B19xxx range.

There is also 2 (of 3) tantalum capacitors that don't seem to be
de-rated particularly well (C11 & C31). - (Yes, they look like
tantalum, the NSN's say they are tant., and their tiny physical size
strongly implies it as well.)

I've a DER DE-5000 and a HV supply (Eico 950B) so I could pull them
and measure DF/ESR/leakage/etc to my hearts content, but if I'm going
to remove them, I'd just as soon put new caps back in circuit.

Suggestions? Comments? Cries of Derision?

Thanks,

David

Re: Tek 576 Curve Tracer HV Transformer winding

Chuck Harris
 

The cores across pretty much everything they made are
equivalent. Some of the later cores had special divots
molded into them for holding a clamp.

-Chuck Harris

ykochcal wrote:

Chuck is the 576 core the same as the 535, 545, and 585? I don't recall off
hand.

If so, there seems to be someone who scrapped a large number of scopes on
the bay and is selling the HV supply assemblies for about $24 in the USA

Searched "Tektronix transformer", sort by best match, but then look for the
worst match at the bottom.

So all is not lost in any case for a 576

John

Re: Tek 576 Curve Tracer HV Transformer winding

Jim Ford
 

Blaze Pizza cooks theirs in 180 seconds, and Pizza 90 does it in 90.  Must be pretty darn hot ovens!  Thin crust only, of course.  Both are excellent pizzas.Sorry to take it so far OT.Jim Ford Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------From: Dave Daniel <kc0wjn@...> Date: 9/15/19 1:06 PM (GMT-08:00) To: TekScopes@groups.io Subject: Re: [TekScopes] Tek 576 Curve Tracer HV Transformer winding On 9/15/2019 3:34 PM, Chuck Harris wrote:> Just remember the ferrite is a ceramic mixture,> so it was once heated much hotter than your oven> will ever go.Ha. This reminds me of Jeff Potter's book "Cooking for Geeks", where he intentionally disables the self-cleaning interlock on his range to see how fast he can cook a pizza. ISTR that he got the oven temperature to well over 600^o.DaveD

Re: Tek 576 Curve Tracer HV Transformer winding

Mlynch001
 

Chuck,

Thanks! That is what I plan to do. I’m glad to know that breaking them can be repaired with super glue. That makes me more at ease with the whole process. I really appreciate you explaining the process in depth. I will post my results.

Sincerely,
--
Michael Lynch
Dardanelle, AR

Re: From 2014: Tektronix Announces Winner of Europe’s Oldest Working Oscilloscope Contest

Alan Ainslie
 

I confirm - alive and well and taking medication for collecting obession.

The Oldest Tek Scope competition seems so long ago - I did not make any fuss at the time but it was quite an event - I have a 511 which did not work and was therefore disqualified (it does now), and was rather surprised that the 511AD won the day.

I do remember at the handover of the sexy new toy that the staff had never seen a CRT scope!  I was pleased to show that a 555 with SA and signal PIs would do mixed domain, as would the 7854 with logic analyser - the staff were amazed. My jibe about no real progress fell on deaf ears.

I also confess to buying the Fiches recently.  I have not got them yet, but will see what we have and see if there is still enthusiasm in the UK to do some automated scanning.  I have The Eddystone Radio Museum and Archive, and although I did not do the work, there was a panic when  factory blueprints were not to be destroyed and were quickly microfiched.  Well after the event the fiches were scanned, but these were individual schematics rather than pages of manuals, so maybe the Tek Fiche task is a much bigger job. But I am sure that we can assemble a small group to look at the challenge and share the outcome.

Regards

Alan

Re: From 2014: Tektronix Announces Winner of Europe’s Oldest Working Oscilloscope Contest

 

Hi Alan,

Let me be the first (of many) on TekScopes to congratulate you on winning the MDO scope. I was also less than impressed by all the ballyhoo when Tek chose to make a big deal of the Mixed Domain concept as something new. I've been mixing domains with 7000 scopes for years. There are other domains the MSO can't do that they chose to ignore because it would have deflated their marketing hype.

I am appalled that the people at the event have never see a CRT scope and that they would be amazed by the things you demonstrated to them. I'm reminded that "Those who cannot remember the past are condemned to repeat it." You did all of us a favor by sticking it to them about the capabilities of the older laboratory scopes.

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Alan Ainslie
Sent: Sunday, September 15, 2019 2:54 PM

I confirm - alive and well and taking medication for collecting obession.

The Oldest Tek Scope competition seems so long ago - I did not make any fuss at the time but it was quite an event - I have a 511 which did not work and was therefore disqualified (it does now), and was rather surprised that the 511AD won the day.

I do remember at the handover of the sexy new toy that the staff had never seen a CRT scope! I was pleased to show that a 555 with SA and signal PIs would do mixed domain, as would the 7854 with logic analyser
- the staff were amazed. My jibe about no real progress fell on deaf ears.

I also confess to buying the Fiches recently. I have not got them yet, but will see what we have and see if there is still enthusiasm in the UK to do some automated scanning. I have The Eddystone Radio Museum and Archive, and although I did not do the work, there was a panic when factory blueprints were not to be destroyed and were quickly microfiched. Well after the event the fiches were scanned, but these were individual schematics rather than pages of manuals, so maybe the Tek Fiche task is a much bigger job. But I am sure that we can assemble a small group to look at the challenge and share the outcome.

Regards

Alan




--
Dennis Tillman W7PF
TekScopes Moderator

Re: 11801 NVRAM

Reginald Beardsley
 

FYI I created a photo album and posted a picture of the 33622A ramp displayed on my 11801 using an SD-26 head at 1 ps/div and 2 mV/div with 1024 samples.

With a trigger signal at 100 kHz, you need a ramp at 100.0001 kHz to test the linearity of the time base. I'm just using the internal timebase, the 33622A set as close as I could and taking the photo at the right moment. It took a couple of tries. I'll try for more rigorous results later.

I'd like to thank be_moulton for suggesting the idea. I had pondered the subject, but lacked the insight needed. It's a great pleasure to have such excellent company join us.

Have Fun!
Reg

Re: From 2014: Tektronix Announces Winner of Europe’s Oldest Working Oscilloscope Contest

Mlynch001
 

Dennis,

Well said!

--
Michael Lynch
Dardanelle, AR

Re: From 2014: Tektronix Announces Winner of Europe’s Oldest Working Oscilloscope Contest

John Williams
 

Hi Alan very pleased to meet you. Thank you for your contributions and congratulations on your win. Umm, I was wondering if you could share the name of the anti-collection medication? Thanks. John

Re: From 2014: Tektronix Announces Winner of Europe’s Oldest Working Oscilloscope Contest

Dave Voorhis
 

On 15 Sep 2019, at 23:56, John Williams <books4you@...> wrote:

Umm, I was wondering if you could share the name of the anti-collection medication?
I bet it’s called “Angry Spouse.” :-)

Re: From 2014: Tektronix Announces Winner of Europe's Oldest Working Oscilloscope Contest

Craig Sawyers <c.sawyers@...>
 

Hi Alan very pleased to meet you. Thank you for your contributions and congratulations on your win.
Umm, I was wondering if you could share the name of the anti-collection medication? Thanks. John
I'll answer that - there is no known cure!

Craig

Re: From 2014: Tektronix Announces Winner of Europe’s Oldest Working Oscilloscope Contest

 

Even more powerful is "Angry Spouse 2.0".

On 9/15/2019 7:14 PM, Dave Voorhis wrote:
On 15 Sep 2019, at 23:56, John Williams <books4you@...> wrote:

Umm, I was wondering if you could share the name of the anti-collection medication?
I bet it’s called “Angry Spouse.” :-)